A wide variety of collets are utilized on routers in order to removably affix a rotary cutting tool to the router drive shaft. Router collets can be classified in two main categories. Collets which are integrally formed as part of the drive shaft, and collets which are a discrete separate element which are trapped between and cooperate with the drive shaft and a nut.
A problem associated with router collets utilizing a discrete collet element design is that the collet once tightened securely grips both the shank of the cutting tool and the cooperating frusto-conical surface which can be formed either in the collet nut or in the body member oriented on the end of the drive shaft. In spite of the nut being loosened, the collet and cooperating frusto-conical surface remain locked together. In order to remove the cutting tool it is typically necessary to tap the cutter or to dislodge the discrete collet and cooperating member.
An object of the present invention is to provide a router collet assembly having a discrete collet which automatically releases the rotary cutting tool enabling the tool to be freely removed and replaced once the collet nut is rotated in an unloosening direction relative to the body at a predetermined distance.